Elevator safety apparatus



7, 1957 Y J. c. PHILLIPS I 2,804,175

ELEVATOR SAFETY APPARATUS Filed Jan. 6. 1954 2 Shets-Sheet l f fighi.

INVENTOR.

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Aug. 27, 1957 J. c. PHILLIPS ELEVATOR SAFETY APPARATUS 2 Sheets-Sheet. 2

Filed Jan. 6, 1-954 M W a m W J w United States Patent 2,804,175ELEVATOR SAFETY APPARATUS Joseph C. Phillips, Baltimore, Md. ApplicationJanuary 6, 1954, Serial No. 402,560 4 Claims. Cl. 187-86) This inventionrelates to elevators or lifts for carrying persons and material from oneheight to another through a vertical plane. It is particularly intendedfor such equipment, used in conjunction with the construction ofbuildings and serving as a portable or transportable arrangement for thepurpose, and the delivery of material needed to the various heights.

While a number of devices have been designed and used in connection withthe prevention of elevators from falling and doing damage, when thehoisting cables break such have in most instances proved ineffectivebecause of their tendency to collapse the columns supporting and guidingthe elevator platform, as well as slip or break the braking devicesinvolved. In this invention the breaking of the hoisting cables allowsbraking device to resiliently and powerfully react and work on thesupporting columns in such a manner as to avoid collapsing and spreadingthem apart, while at the same time providing for an effective restraintagainst further falling of'the platform.

An object of this invention is to provide a new and improved safetycontrol for an elevator that will operate positively and effectively, beinstallable economically, yet be simple, compact and attractive indesign.

Anotherobject of this, invention is. to provide anew and improve safetycontrol for an elevator platform that will act on the supporting columnsof the elevator structure without injury to themselves or the control.

A further object of the invention is to provide a new and improvedsafety control for an elevator platform that will employ an eccentricfrictional surface in contact with the supporting columns of theelevator structure immediately operable when the hoisting cables of theelevator break and work efficiently in spite of oil and grease on thecontact surfaces.

An additional and important object of the invention is to have a safetycontrol attached to the platform and contactable with the supportingcolumns of the elevator structure, so arranged that the operation of thecontrol under emergency conditions will not cause the columns to spreadordistort into misalignment or form enough to interfere with the properaction of the device.

Other objects of the invention will become apparent as the details ofits construction and the principles of its operative functions areexplained.

For a better understanding of the invention and the objects thereof,reference is made to the accompanying drawings. These drawingsillustrate a particular form of the construction preferably adopted,while the following description indicate how it is made and the basis ofits functioning.

In the drawings:

Fig. 1 is a front elevation of an elevator with safety controlsembodying this invention;

Fig. 2 is a perspective view of one spring element; Fig. 3 is aschematic of one spring element in one operative position;

ice

Fig. 4 is a schematic of said spring element of Fig. 3

in a second operative condition; 7

Fig. 5 is a schematic of said spring element of Fig. 3 in a thirdoperative position; f

Fig. 6 is a side elevation of an enclosure with a side thereof brokenaway;

Fig. 7' is a section along line Fig. 8 is a detail of a pawl.

Similar reference numerals refer to the same parts throughout thedrawings. i

In the construction shown in the drawings, an elevator carrier consistsof a flat horizontal platform 10, that is supported underneath by astructural member 11. Vertical struts 12 extend from the member 11upward and terminate in a channel cross beam 14, forming a ridge baracross the carrier and serving as a suspension member to 'which thehoisting cable 13 can be conveniently 7-7 of Fig; 1; and

attached. A thimble 15 at the end of the cable is'held' by a bolt 16 tothe beam 14. This single cable 13, is carried to the overhead pulleysand from thence to the winch supplying the power to lift the elevator.This follows conventional procedure and therefore is not shown, as thedetails are well known to'those skilled in the art.

Coupled to the cable 13 is a clamp 34'bolted securely fulcrum plates 20.When the chains exert a pull on the bars 18 in the angular plane theycompress (or extend, as preferred) their individual coil springs 21 andtension them so they induce a resilientforce tending to push the bars'18 downwardly. This is resisted when the cable 13, lifts against them.This force will induce'leverage on the bars and lift up on the shortends 22. The springs 21 are supported on a bolted frame 32 attached tothe ridge beam 14. The short ends 22 are attached to oscillatablepositioned shackles or saddles 23 holding brake cams24 by part 37. Thesecams are supported off center by pivots 35 mounted on enclosure 30. Thepivots 35 are heldbetween the arms 25 of the saddles which are madebifurcated for the purpose. The front and rear faces 26 and 27 of thecams respectively are preferably rounded at 27 and serrated at 36 toprovide a roughened surface resistance.

U-formed enclosures 30 serve to encompass and support the cams 24 and indefinite relation to the ends of the ridge bar 12. This arrangementaligns the cams so their faces 26 can engage the periphery of theirrespective pipe guiding column 28 on one side and inner surface 29 ofthe enclosure 30 by the opposite face 27. The inner surface 31 of eachenclosure 30 is aligned close to the peripheral surface of therespective column 28, opposite to face 29. The cams are adjusted so thatnormally they will not contact the surfaces of the encolsures 30 and thepipe columns 28, and thus will not interfere with the free running ofthe elevator carrier in its usual vertical travel. However, when thehositing rope 13 breaks and loosens up on the chains and release bars18, the latter allows the coil springs 21 to force the earns 24 upwardfrom the position indicated in Figure 3 or 4 to that shown in Figure 5.The springs 21 push down on a rod 33 and pivots the cams on the fulcrumsso that powerful contact effects bring the faces 26 and 27 against theperipheral faces of the column 28 and face 29 of enclosures 30respectively. This brakes the carrier and quickly brings it to a stop.

The inner surface 31 of the enclosure is preferably roughened, serratedor faced with welding 134 to add to frictional and wear resistance. Whenthe cams make the emergency contact they exert pressure against the'Patented Aug. 2'1, 1957 inner surfaces 29 and reacting against the pipethey bring the enclosure-over enough to make the surfaces 31 braceagainst the opposite side of the pipe. This distributes the effect andprevents the crushing of ,the pipe fcolumn 28 and prevents course tobe;understood slightly longer than the jammed against the pipes '28 whenthe release bars are loosened at the breaking of the hoisting rope. Themovement of g the carrier falling and its momentum brings the cams andtheir serrated ,surfaces into such engagement with the toe. stop. I

The devices are returned tooper-ati-ve conditionaftet repairs have beenmade,v by replacing thehoistingrope andpulling up on the chains 17 withthe release bars into position for emergency tension, and futureoperation. When the hoisting rope normally holds the carrier in liftingpositions, it places theemer-gency braking mechanisms underresilientjtension, ready to actuate when released. 7 7 a *Thecharacteristics. of the device are important because they include pluralwearing surfaces for emergency use; a cam-like wedge for positive yetnot too abrupt braking effect; the use of the guide columns for brakingcoordination without danger of their being destructively damaged duringthe period of braking; components of the braking mechanism made readilyaccessible for facile inspection, adjustment,; replacement and repair,and designed to operate effectively in spite of grease and otherlubricants covering the braking surfaces and components While but onegeneral form of the invention is. shown in the drawings and described inthe specification, it is not desired to limit this application forpatent to this particular form as it is appreciated that other forms .ofconstruction could, be made that would use the same principles and comewithin the scope of the appended claims.

Having thusrdescribed the invention, what is claimed is:

1. The combination, with an elevator, of emergency safety mechanism forpreventing uncontrolled descent of the elevator; said elevatorcomprising a pair of oppositely disposed hollow columns, a platform, across beam, a pair of struts supporting said cross beam above theplatthat the length of each cam is its moving out of alignment; :It isof space .it spans;v They ,become pipe column, as to bring the carrierform and each of said struts embracing one of said colstraddling one ofsaid hollow columns, a second pair of pivot elements each connecting oneof said cam members to one ofsaid U-shaped members, means connecting theother end of each of said .levers to said cable and resilient meanstending to swing said other ends of said levers toward said cross beam,said U-shaped members and said cam members having serrated portionsconfronting said columns; the pivots connecting the cam members to theU-shaped members being positioned to cause lifting of the saddles toswing the serrated portions of the cam members into contact with saidcolumns and the length of the cam members being such as to cause suchcontact to move the U-shaped members to bring the serrated portionsthereof into contact with portions of the hollow columns opposite to theportions engaged by said cam members. '2'. A combination of the type setforth in claim 1, in which the means connecting said levers to saidcable include a clamp secured to said cable and flexible meansconnecting said other ends of the levers to said clamp.

3. A combination of the type set forth in claim 2, which includes a pairof frames secured to said cross beam, and supporting said resilientmeans in position to act on said levers.

'4. A combination of the type set forth in claim 3, in which weldingmaterial is applied to a partofeach of the serrated portions of theU-shaped members.

References Cited in the file of this patent UNITED STATES PATENTS741,481 Fulwider Oct. 13, 1903 1,163,239 Iron Dec. 7, 1915 1,373,944Boeh'ck Apr. 5, 1921 1,515,452 Webb et al. Nov. 11, 1924 2,629,461

Moyer Feb. 24, 1953

